Could the multi-line chart use the attachEvent?

if yes, could you give me an example??

What event handler do you need to attach ?

Clicking a dot on the chart to open a new window that shows the details of that is what I want.

I need to attach the onClick eventhandler.

You may set onItemClick event:

chart.attachEvent("onItemClick",function(itemId){ /*your code here*/ })

I think it currently does not work when multiple series present.
See http://forum.dhtmlx.com/viewtopic.php?f=8&t=18463